The engine immobiliser system is designed to prevent the vehicle from being stolen. This system uses a transponder key ecu that stores the key codes of authorized ignition keys. If an attempt is made to start the engine using an unauthorized key, the ecu sends a signal to the ecm to prohibit fuel delivery and ignition, effectively disabling the engine.

The transponder key coil receives this signal, the transponder key amplifier amplifies it, and then the signal is transmitted to the ecu. The ecu matches the key's id code with the vehicle's id code, which was previously registered in the ecu and then communicates the results to the ecm using sfi communication.
Engine immobiliser system
How to proceed with troubleshootingFootwell light circuit
Description
The main body ecu receives information regarding the door lock position
switch and ignition switch, and
turns on each foot light.
Wiring diagram
Inspection procedure
Perform active test by intelligent tester (main body ecu)
Connect the intelligent tester (with can vim ...
Terminals of ecm
Hint:
The standard normal voltage between each pair of ecm
terminals is shown in the table below. The appropriate
conditions for checking each pair of terminals are also
indicated. The result of checks should be compared with the
standard normal voltage for that pair of terminals, displayed ...
Back door outside garnish
Components
Removal
Disconnect cable from negative battery
terminal
Caution:
Wait at least 90 seconds after disconnecting the
cable from the negative (-) battery terminal to
prevent airbag and seat belt pretensioner activation.
Remove back door center garnish (see page
ed-5 ...